1. Field of the Invention
This invention relates to instruments for use in medical procedures. More particularly, this invention relates to a set of surgical instruments substantially for dissection and retraction in minimally invasive surgical procedures such as laparoscopy and mini-laparotomy.
2. Background Information
Surgical tools are commonly used in minimally invasive surgical procedures, such as mini-laparotomy, laparoscopic or thoracoscopic surgery, to provide mechanical handling of tissue. For example, during surgery on or adjacent to the spine the surgeon should have clear access to the desired intervertebral discs or vertebrae for purposes of discetomy, vertebrectomy, spinal decompression, or placement of fusion disc devices, prosthetics, or other hardware. Surgical tools may be used for dissection and/or retraction of blood vessels or other bodily tissues to provide clear access to the desired area. In some spinal procedures, the surgical entry point is on the abdominal side of the patient""s body, so the tools must provide clearance so that the entire diameter of the abdominal cavity may be traversed for performance of the surgical procedure.
In some minimally invasive surgical procedures, such as laparoscopic or thoracoscopic procedures, one or more trocars typically penetrate and/or are maintained or mounted in the wall of the body cavity to provide access for the surgical tools during the procedure. The trocars may form or act as ports into the body cavity for insertion and manipulation of surgical instruments. Some surgical instruments, particularly those with sharp tips or edges, are inserted and moved to a desired working location in the body in hollow tubes or sheaths to reduce the risk of harming other blood vessels or organs during traversal of the body. A video camera may be mounted on a laparoscope which is passed through a trocar port for visualization of the procedures in the body cavity on a monitor. Alternatively, an X-ray or other visualization system may be used to view the procedure, including the position of instruments relative to the surgical site, on a suitable monitor.
Generally it is desirable to reduce the number of trocar ports used during a surgical procedure to reduce trauma to the patient. For this reason, a plurality of surgical tools, including tools dedicated to a specific function, adapted to be inserted through a trocar are preferred so that blood vessels, tissue, and the area of the surgical procedure may be manipulated through a small number of trocar ports or through a mini-laparotomy incision.
A variety of tools, such as retractors, forceps, graspers, suture needles, and pins, currently exist and may be available for use during abdominal or thoracic procedures. Such tools, however, have certain deficiencies when minimally invasive access methods are used. One problem with available surgical tools is that they are not properly shaped for optimal harmless manipulation of blood vessels and other bodily tissue during laparoscopic or thoracoscopic procedures. Another problem with some surgical tools which might be appropriately shaped is that they do not fit through the tubes or trocars, so it can be difficult to traverse the body to reach the desired working location. The typical trocar is approximately 11 to 12 or less millimeters in diameter, and the hollow tubes therein are of approximately the same diameter. Some surgical tools have working ends of greater than 12 millimeters in length, and it would be difficult or impossible to insert these tools through typical trocars and tubes.
A need exists for surgical tools and methods which reduce potential trauma associated with surgery, including minimally invasive surgical procedures, and which aid the surgeon in manipulating blood vessels and tissue during surgical procedures. More specifically, a need exists for surgical tools for dissection and retraction that are shaped to allow a surgeon to manipulate blood vessels and other bodily tissue without harming the patient. The tools should also be properly shaped to perform specific functions or procedures conveniently and with minimal risk to the patient, yet they should be usable through typical trocars, ports or short incisions (e.g., incisions of the type used in mini-laparotomy).
The present invention provides instruments for use in surgical procedures. In one embodiment, the instruments of the present invention comprise a kit of instruments well-suited for use in minimally invasive surgical procedures, particularly such procedures involving or conducted near the spine. The kit includes at least one or more of the retractors described herein, one or more of the dissectors described herein and one or more of the pins described herein. It is anticipated that the kit would be available to surgeons through, for example, typical hospital or clinic supply arrangements, in the form of a sterilized prewrapped package of one or more of the instruments or selected embodiments of the instruments.
Each of the instruments comprising the kit is an embodiment of the present invention. One embodiment, the retractor(s), comprises a working end having a generally central longitudinal axis and a surface generally transverse to the axis, the surface being defined by a generally toroidal shape having a concave portion and a convex portion, the concave portion having a selected degree of openness, wherein the convex portion of the surface does not extend beyond a line parallel with the longitudinal axis along an outer diameter of the working end adjacent to the surface, and the surface has a continuous edge having a first end at a shoulder and a second end at the shoulder and spaced from the first end. This embodiment of the invention may further comprise a shaft coupled to the working end for handling the surgical instrument. The working end and shaft may be unitary (i.e., formed as a single piece), they may be permanently coupled or connected, or they may be separably joined.
In another embodiment, the retractor comprises a working end having a generally longitudinal axis, the working end being defined by a generally curved surface along the longitudinal axis, wherein the curved surface has a concave portion and a convex portion, and wherein the working end has a generally flat tip. Again, the working end may be formed as one piece with a shaft or handle, it may be permanently joined to a shaft, or it may be separably joined to a shaft.
Another embodiment, of the invention, the dissector(s), comprises a working end having a generally central longitudinal axis and a surface generally transverse to the axis, wherein the surface is generally spatulate and oval, and wherein the surface is set at a selected angle relative to the axis. In this embodiment, the surface may also be offset in reference to a shaft.
Another embodiment of the invention, the pin(s), comprises a straight pin for being placed or driven into bone, the pin having a sharp tip and a number of steps generally adjacent to the tip, as well as circular markings or etchings adjacent to each step separated at a 1 cm distance. Along the length of the pin, from the tip, the pin increases generally incrementally in diameter with each step, and has a first end opposite the sharp tip for hammering. In this embodiment, the invention may further comprise a hollow guide tube for removably receiving the pin as the pin is moved to the site of use, the pin being longer in length than the guide tube.
An advantage of the instruments of the present invention, particularly in kit form, is that they facilitate performing minimally invasive surgical procedures, particularly spinal procedures, wherein each instrument is well adapted for a particular function or manipulation of a particular tissue.
For example, the retractors are well suited for manipulation of tissues, for example, tissue adjacent or immediately adjacent to the spine, the common iliac artery and vein, segmental vessels or the cystic duct. The dissectors are well suited for manipulation tissues such as the mid-sacral and segmental blood vessels or the cystic, and the pins may be driven into bone, including vertebrae, to support or hold tissue(s) in a desired position during a surgical procedure.
Another advantage of the instruments of the present invention, particularly the retractors, is that they include a working end at least a portion of which is radiolucent, i.e., permeable to radiation, whereby a surgeon may have an improved visualization of other devices in use during a procedure and examined or displayed on an imaging system.
Another advantage of the instruments of the present invention, particularly the retractors and dissectors, is that they have smooth continuous edges, smooth working surfaces, and smoothly rounded edges and tips to reduce potential trauma to delicate tissue.
Other features and advantages of the surgical instruments of the present invention will become more fully apparent and understood with reference to the following description and drawings, and the appended claims.